Implement initial chrome.browserAction.openPopup API.

chrome/renderer/resources/extensions/browser_action_custom_bindings.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Custom binding for the browserAction API.
 
 var binding = require('binding').Binding.create('browserAction');
 
 var setIcon = require('setIcon').setIcon;
+var getExtensionViews = requireNative('extension').GetExtensionViews;
 
 binding.registerCustomHook(function(bindingsAPI) {
   var apiFunctions = bindingsAPI.apiFunctions;
 
   apiFunctions.setHandleRequest('setIcon', function(details, callback) {
     setIcon(details, callback, this.name, this.definition.parameters,
         'browser action');
   });
+
+  apiFunctions.setCustomCallback('openPopup',
+                                 function(name, request, response) {
+    if (response && request.callback) {
+      var callback = request.callback;
+      // TODO(justinlin): Figure out how to ensure the popup is already open
+      // before calling this.

[Matt Perry, 2013/10/11 22:22:53]

The browser side will have to do that (add a notification observer to wait for
its ExtensionHost/RenderViewHost to load before calling the callback).

[justinlin, 2013/10/16 07:06:48]

Done.

+      setTimeout(function() {
+        var views = getExtensionViews(-1, 'POPUP');
+        callback(views.length > 0 ? views[0] : null);
+      }, 50);
+    } else {
+      request.callback(null);
+    }
+    request.callback = null;
+  });
 });
 
 exports.binding = binding.generate();